%0 Journal Article %A Tomashevskaya, O. L. %A Solovyev, A. G. %A Karpova, O. V. %A Fedorkin, O. N. %A Rodionova, N. P. %A Morozov, S. Yu. %A Atabekov, J. G. %T Effects of sequence elements in the potato virus X RNA 5′ non-translated αβ-leader on its translation enhancing activity %D 1993 %J Journal of General Virology, %V 74 %N 12 %P 2717-2724 %@ 1465-2099 %R https://doi.org/10.1099/0022-1317-74-12-2717 %I Microbiology Society, %X The 5′ non-translated αβ-leader sequence of potato virus X RNA consists of two regions: the α sequence (41 nucleotides with no G) and the β sequence (42 nucleotides upstream from AUG). The αβ-leader has been shown to enhance strongly the expression of adjacent genes in chimeric mRNAs. This phenomenon has been postulated to be due to the unpaired conformation of the 5′-terminal 30 nucleotides and/or to the presence within the α region of the CCACC pentanucleotide complementary to the 3′-terminal conserved structure of 18S rRNA. Different derivatives of αβ-leader have been constructed for use in determining the contribution of separate elements of the αβ sequence to translational enhancement. It was found that deletion of the α sequence large fragment which was supposed to be unfolded did not reduce the Δαβ-leader enhancement activity. Moreover, translational enhancement was greater for this derivative. Deletion of the β sequence resulted in a considerable increase in activity of the α-leader showing that the β region was dispensable for translation. Disruption or ‘masking’ of CCACC led to inactivation of the αβ-leader as a translational enhancer. Thus, we identified the CCACC pentanucleotide as the primary motif responsible for the translation enhancing ability of αβ-leader. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-74-12-2717